What's the best AI writing assistant for drafting product docs and internal updates?

For drafting product docs and internal updates, the “best” AI writing assistant depends mostly on where your team already works and how much control you need over tone, permissions, and source material.

My short recommendation

• Best overall for teams already in Google Workspace or Notion: ChatGPT or Notion AI
• Best for polished business writing and summaries inside docs/email: Microsoft Copilot
• Best for knowledge-base style docs and team collaboration: Notion AI
• Best for security/compliance-heavy orgs: Microsoft Copilot or Google Gemini for Workspace
• Best for flexible drafting, brainstorming, and rewriting: ChatGPT

What I’d choose by use case

1) Product docs

You usually want:

• clear structure
• versioning
• fast rewriting
• consistency of tone
• easy collaboration with PM, eng, support

Best picks:

• Notion AI if your docs live in Notion
• Google Gemini for Workspace if your docs live in Google Docs
• Microsoft Copilot if your docs live in Word/SharePoint
• ChatGPT if you want the strongest drafting help and then paste into your doc system

2) Internal updates

You usually want:

• concise status summaries
• bullet-point formatting
• tone adjustment for leadership vs team
• fast turnarounds from notes/chat logs

Best picks:

• ChatGPT for turning rough notes into clean updates
• Microsoft Copilot if updates are written in Outlook/Teams/Word
• Notion AI if updates are tracked in Notion

Practical takeaway

If you want one tool that’s generally strongest at drafting, editing, and adapting tone, I’d pick ChatGPT.

If you want the most seamless experience inside a document ecosystem:

• Notion AI for Notion-centric teams
• Copilot for Microsoft-centric teams
• Gemini for Google-centric teams

If you want, I can also give you:

1. a top 5 comparison table
2. recommendations by budget
3. recommendations by security/compliance
4. the best tool for product managers specifically